2053Lecture8 - Linear Momentum& Conservation...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Linear Momentum & Conservation Conservation Topics of Discussion Topics Linear Momentum Reformulation of Newton’s Second Law Conservation of Linear Momentum Types of Collisions Impulse & the Impulse-Momentum Impulse Theorem Theorem Linear Momentum Linear The linear momentum p, iin the SI units n The kgm/s, of an object with mass m moving at kgm/s of the velocity v is defined by p = mv . Newton’s Second Law and Momentum Momentum (Newton’s Second Law) The time rate The change of an object’s momentum is equal to the average force F acting on the object of mass m, and is given by ∆p F= ∆t . Conservation of Linear Momentum Conservation When no external forces are acting on a system When consisting of colliding objects, the total initial momentum is equal to the total final momentum of the system. of Let mk be the mass of the k-the particle, vki be its Let initial speed and vkf be its final speed, then the principle of linear momentum conservation for a two particle system is given by two m١v١i + m٢v٢i = m١v١ f + m٢v٢ f . Elastic Collisions Elastic Elastic collisions occur when the Elastic conservation of linear momentum and energy hold simultaneously. energy m١v١i + m٢v٢i = m١v١ f + m٢v٢ f Ebefore = Eafter Inelastic Collisions Inelastic Inelastic collisions occur when only the Inelastic occur conservation of linear momentum holds. conservation m١v١i + m٢v٢i = m١v١ f + m٢v٢ f Completely Inelastic Collisions Completely When two objects in a system of objects When stick together, they experience a completely inelastic collision, and the completely and principle of linear momentum conservation states states m١v١i + m٢v٢i = ( m١ + m٢ ) v f Remember that the conservation of energy is invalid for completely inelastic collisions. is Impulse The force F which acts over a time interval ∆t is called the impulse J delivered to a impulse system of particles, and is given by system J = F∆ t. Impulse-Linear Momentum Theorem Theorem A force acting over a time interval ∆t which force changes the speed of the body from vi to vf is equal to the change in momentum of a particle of mass m, that is that F∆ t = mv f − mvi . ...
View Full Document

Ask a homework question - tutors are online